VanderbiltHealth.com: For Patients and Visitors
Vanderbilt University Medical Center: For Employees, Researchers, and Students

Research

Current Studies

Susceptibility of Type 1 Diabetic Adolescents to Noise Induced Hearing Loss
 
In the last two decades diabetes in adolescents has been reported with increasing frequency (SEARCH, 2007). Additionally, adolescent’s exposure to harmful levels of sound has become more common. In particular, the rise in use of portable music players may impose risk for adolescents not aware of the insidious risks of hearing loss imposed by the mixture of elevated sound intensity and prolonged exposure duration (Zogby, 2006). Recent animal studies indicate increased risk in diabetics for hearing loss related to noise and age (e.g., Wu et al., 2009). The combination of increased noise exposure and increased risk of hearing loss may have profound implications for the hearing of diabetics, particularly young diabetics with high levels of noise exposure. Despite this evidence no study has examined the relationship between noise exposure and hearing loss in a human diabetic population. The broad long-term goal of the proposed research is to study the association of diabetes with susceptibility to noise-related hearing loss. The goal of this pilot study is to assess the relationship between diabetes, noise, and hearing loss in a sample population of adolescents/young adults with type 1 diabetes. Three specific aims will (1) characterize auditory function using methods sensitive to subtle changes in cochlear and neural function; (2) determine noise exposure via questionnaire/activity cards and personal dosimeter measures to estimate noise-dose risk for auditory damage; and (3) explore associations between diabetic control and measures of hearing, cochlear function, auditory neural integrity, and susceptibility to noise related hearing loss. These aims will be accomplished through evaluation of 50 experimental subjects aged 12-22 years diagnosed with type 1 diabetes and 50 matched control subjects. New techniques that are uniquely sensitive to subtle changes in auditory cochlear and neural function will be used. The determination of factors associated with hearing loss in diabetics has direct implications on reducing susceptibility and severity of hearing loss in the diabetic population. In addition, this study will provide an examination of the ability of the most sensitive outcomes measures available to detect damage in an etiology representative of compromised auditory metabolic function.
 
 
Recent Studies
 
Spankovich, C., Hood L.J., Silver, H., Lambert, W., Flood, V., and Mitchell, P. (In preparation.) Associations between Dietary Intakes and Auditory Function in Older Australians from the Blue Mountains Hearing Study
Evidence from animal models suggests that oxidative stress and vascular integrity are important in the pathogenesis of sensorineural hearing loss (SNHL) and that dietary nutrients that have roles in these processes may influence susceptibility to SNHL. The purpose of this study was to examine associations between total nutrient intakes and auditory function outcomes in an older human population. Descriptive characteristics and dietary data from food frequency questionnaires were collected from 2111 Australians aged 49-99 years in a cross-sectional study design and analyzed for associations with auditory function outcomes (ie, otoacoustic emissions and pure tone averages measured in a sound-treated room by a trained audiologist). Increased carbohydrate, vitamin C, vitamin E, riboflavin, magnesium and lycopene intakes were significantly associated with better auditory function. Increased cholesterol, fat and retinol intakes were significantly associated with poorer auditory function. These data demonstrate that nutrients that function in oxidative homeostasis and vascular integrity are associated with auditory function. The findings indicate that further investigation is warranted to determine which nutrients are predictive of SNHL in humans as well as how combinations of nutrients interact with auditory function.
 
Spankovich, C., Hood, L.J., Grantham D.W., and Polley, D.B. (2008). Application of frequency modulated chirp stimuli for rapid and sensitive ABR measurements in the rat. Hearing Research 245, 92-97.
Rodents have proven to be a useful model system to screen genes, ototoxic compounds and sound exposure protocols that may play a role in hearing loss. High-throughput screening depends upon a rapid and reliable functional assay for hearing loss. This study describes the use of a frequency modulated (FM) chirp stimulus as an alternative to the click to derive a rapid assessment of auditory brainstem response (ABR) threshold in the rodent. We designed a rising frequency A-chirp based upon the spatial mapping of preferred frequency along the rat basilar membrane to provide a more synchronous and equipotent input across the length of the cochlea. We observed that the ABR wave I and wave IV amplitudes evoked by the A-chirp were significantly greater than the click and that A-chirp minimum response thresholds were lower than the click. Subsequent analyzes compared the efficacy of the A-chirp to linear, time-reversed and amplitude-reversed chirps and confirmed that the A-chirp was most effective chirp configuration. These data suggest that the A-chirp may be optimally suited as a single screening broad frequency stimulus for rapid ABR threshold estimations in the rodent and could serve to complement more detailed frequency-specific physiologic and behavioral estimates of hearing threshold.
 
Past Publications

Publications related to MOC reflex and OAE suppression

Berlin CI, Hood LJ, Cecola RP, Jackson DF, Szabo P. 1993. Does Type I afferent neuron dysfunction reveal itself through lack of efferent suppression? Hear Res 65:40-50.
 
Berlin CI, Hood LJ, Wen H, Szabo P, Cecola RP, Rigby P, Jackson DF. 1993. Contralateral suppression of non-linear click-evoked otoacoustic emissions in humans. Hear Res 71:1-11.
 
Berlin CI, Hood LJ, Hurley A, Wen H. 1994. Contralateral suppression of otoacoustic emissions: An index of the function of the medial olivocochlear system. Otolaryngol-Head Neck Surg 100:3-21.
 
Berlin CI, Hood, LJ, Hurley A, Wen H, Kemp DT. 1995. Binaural noise suppresses click-evoked otoacoustic emissions more than ipsilateral or contralateral noise. Hear Res 87:96-103.
 
Hood LJ, Berlin CI, Hurley A, Cecola RP, Bell B.   1996. Contralateral suppression of click-evoked otoacoustic emissions: Intensity effects.   Hear Res 101:113-118.
 
Hood LJ, Berlin CI, Hurley A, Wen H. 1996. Suppression of otoacoustic emissions in normal hearing individuals. Chapter in Berlin CI (Ed), Hair Cells and Hearing Aids. San Diego: Singular Press. Pp.57-72.
 
Hood LJ, Berlin CI. 1996. Central auditory function and disorders. In JL Northern (Ed), Hearing Disorders, Allyn and Bacon.
 
Hood LJ. 1998. An overview of neural function and feedback control in human communication. J. Commun. Dis 31:1-10.
 
Hood LJ. 1998. The role of otoacoustic emissions in identifying carriers of hereditary hearing loss. Chapter in Berlin CI (Ed), Otoacoustic Emissions: Basic Science and Clinical Applications. San Diego: Singular Publishing Group.
 
Morlet T, Goforth L, Hood LJ, Ferber C, Duclaux R, Berlin CI. 1999. Development of human cochlear active mechanism asymmetry: Involvement of the medial olivocochlear system. Hear. Res. 134:153-162.
 
Hood LJ. 1999. A review of objective methods of evaluating auditory neural pathways. Laryngoscope 109:1475-1478.
 
Gravel JS, Hood LJ. 1999. Pediatric audiologic assessment. In Musiek FE, Rintelmann WF: Contemporary Perspectives in Hearing Assessment. Boston: Allyn and Bacon.
 
Hood LJ, Berlin CI, Goforth-Barter L, Bordelon J, Wen H. 1999. Recording and analyzing efferent suppression of transient-evoked otoacoustic emissions. In Berlin CI: The Efferent Auditory System. San Diego: Singular Publishing Group.
 
Hood LJ, Berlin CI, Goforth-Barter L, Bordelon J. 1999. Clinical application of auditory efferent studies. In Berlin CI: The Efferent Auditory System. San Diego: Singular Publishing Group.
 
Hood LJ. Clinical applications of efferent suppression of otoacoustic emissions. 2001. In Glattke T and Robinette M. Otoacoustic Emissions. Amsterdam: Thieme Publishers.
 
Hood LJ, Berlin CI. 2001. Auditory neuropathy (auditory dys-synchrony) disables efferent suppression of otoacoustic emissions. In Starr A and Sininger YS. Auditory Neuropathy. San Diego: Singular Publishing Group.
 
Hood LJ, Berlin CI. 2002. Clinical applications of otoacoustic emissions. In Berlin CI, Hood LJ, and Ricci A (Eds). Hair Cell Micromechanics and Otoacoustic Emissions: New Developments. San Diego: Singular Publishing – Thomsen Learning. Pp.121-137.
 
Berlin CI, Hood LJ, Jeanfreau J, Morlet T, Brashears S, Keats B. 2002. The physiological bases of audiological management. In Berlin CI, Hood LJ, and Ricci A (Eds). Hair Cell Micromechanics and Otoacoustic Emissions: New Developments. San Diego: Singular Publishing – Thomsen Learning. Pp. 139-154.
 
Hood LJ, Berlin CI, Bordelon J, Rose K. 2003. Patients with auditory neuropathy/dys-synchrony lack efferent suppression of transient evoked otoacoustic emissions. Journal of the American Academy of Audiology 14:302-313.
 
Brashears SM, Morlet TG, Berlin CI, Hood LJ. 2003. Olivocochlear efferent suppression in classical musicians. J. Amer. Acad. Audiol. 14:314-324.
.
Berlin CI, Hood LJ, Morlet T, Wilensky D, St. John P, Montgomery E, Thibodeaux M. 2005. Absent or elevated middle ear muscle reflexes in the presence of normal otoacoustic emissions: A universal finding in 136 cases of auditory neuropathy/dys-synchrony. Journal of the American Academy of Audiology. 16:546-53.
 
Hood LJ. 2007. Clinical applications of efferent suppression of otoacoustic emissions. In Glattke T and Robinette M. Otoacoustic Emissions, Third Edition. Amsterdam: Thieme Publishers.
 
Berlin CI, Hood LJ. 2009. Current physiologic bases of audiologic interpretation and management. In Katz J, Burkard R, Hood LJ, Medwetsky L, Eds. Handbook of Clinical Audiology, Sixth Edition.
 
Publications related to auditory neuropathy/dys-synchrony (AN/AD)
 
1. Berlin CI, Bordelon J, St. John P, Wilensky D, Hurley A, Kluka E, Hood LJ. 1998. Reversing click polarity may uncover auditory neuropathy in infants.   Ear and Hearing 19:37-47.
 
2. Berlin CI, Goforth-Barter L, St. John P, Hood LJ. 1999. Auditory neuropathy: Three time courses after early intervention. Abstracts of the Association for Research in Otolaryngology 22:169.
3. Berlin CI, Hood LJ. 2009. Current physiologic bases of audiologic interpretation and management. In Katz J, Burkard R, Medwetsky L, Hood LJ, Eds. Handbook of Clinical Audiology, Sixth Edition.
 
4. Berlin CI, Hood LJ, Cecola RP, Jackson DF and Szabo P. 1993. Does Type I afferent neuron dysfunction reveal itself through lack of efferent suppression? Hearing Research 65:40-50.
 
5. Berlin CI, Hood LJ, Hurley A, Wen H. 1994. Contralateral suppression of otoacoustic emissions: An index of the function of the medial olivocochlear system. Otolaryngol-Head Neck Surg 100:3-21.
 
6. Berlin CI, Hood LJ, Hurley A, Wen H. 1996. Hearing aids: Only for hearing-impaired patients with abnormal otoacoustic emissions. Chapter in Berlin CI (Ed), Hair Cells and Hearing Aids. San Diego: Singular Publishing Group, Inc.
 
7. Berlin CI, Hood LJ, Hurley A, Wen H, Kemp DT. 1995. Binaural noise suppresses click-evoked otoacoustic emissions more than ipsilateral or contralateral noise. Hearing Research 87:96-103.
 
8. Berlin CI, Hood LJ, Jeanfreau J, Morlet T, Brashears S, Keats B. 2002. The physiological bases of audiological management. In Berlin CI, Hood LJ, and Ricci A (Eds). Hair Cell Micromechanics and Otoacoustic Emissions: New Developments. San Diego: Singular Publishing – Thomsen Learning. Pp. 139-154.
 
9. Berlin C, Hood L, Morlet T, Den Z, Goforth L, Tedesco S, Li L, Buchler K, Keats B. 2000. The search for auditory neuropathy patients and connexin 26 patients in schools for the Deaf. Abstracts of the Association for Research in Otolaryngology 23:23-24.
 
10. Berlin CI, Hood LJ, Morlet T, Rose K, Brashears S. 2003. Auditory neuropathy/dys-synchrony: Diagnosis and management. Mental Retardation and Developmental Disabilities Research Reviews.
 
11. Berlin CI, Hood LJ, Morlet T, Wilensky D, St. John P, Montgomery E, Thibodeaux M. 2005. Absent or elevated middle ear muscle reflexes in the presence of normal otoacoustic emissions: A universal finding in 136 cases of auditory neuropathy/dys-synchrony. Journal of the American Academy of Audiology. 16:546-53.
 
12. Berlin CI, Hood LJ, Morlet T, Li L, Wilensky D, Rose K, Taylor-Jeanfreau J, Keats BJB, St. John P, Montgomery E, Shallop J. An analysis of 260 patients with auditory neuropathy/dys-synchrony. Submitted 2009.
 
13. Berlin C, Hood L, Rose K. 2001. On renaming auditory neuropathy as auditory dys-synchrony: Implications for a clearer understanding of the underlying mechanisms and management options. Audiology Today 13:15-17.
 
14. Berlin CI, Keats BJB, Hood LJ, Gregory P, Rance G. 2007. Auditory Neuropathy/Dys-synchrony (AN/AD). Chapter 4 in Schwartz S. (Ed). Choices in Deafness: A Parents' Guide to Communication Options, Third Edition.  Bethesda MD: Woodbine House.
 
15. Berlin CI, Li L, Hood LJ, Morlet T, Rose K, Brashears S. 2002. Auditory neuropathy/dys-synchrony: After the diagnosis, then what? Seminars in Hearing 23:209-214.
 
16. Berlin CI, Morlet T, Hood LJ. 2003. Auditory neuropathy/dys-synchrony: Its diagnosis and management. Pediatric Clinics of North America 50: 331-340.
 
17. Cheng X, Li L, Brashears S, Morlet T, Ng SS, Berlin C, Hood L, Keats B. 2005. Connexin 26 variants and auditory neuropathy/dys-synchrony among children in schools for the deaf. American Journal of Medical Genetics. 139:13-18.
 
18. Hood LJ. 1998. An overview of neural function and feedback control in human communication. J. Commun. Dis 31:1-10.
 
19. Hood LJ. 1998. Auditory neuropathy: What is it and what can we do about it? The Hearing Journal 51:10-18.
 
20. Hood LJ. 1999. A review of objective methods of evaluating auditory neural pathways. Laryngoscope 109:1475-1478.
 
21. Hood LJ. 2001. Clinical applications of efferent suppression of otoacoustic emissions. In Glattke T and Robinette M. Otoacoustic Emissions. Amsterdam: Thieme Publishers.
 
22. Hood LJ. 2002. Auditory neuropathy/auditory dys-synchrony: New insights. The Hearing Journal 55:10-18.
 
23. Hood LJ. 2002. Audiology Awareness: Auditory Neuropathy/Auditory Dys-synchrony. Online publication by Audiology Online for Audiology Awareness.
 
24. Hood LJ. 2007. Clinical applications of efferent suppression of otoacoustic emissions. In Glattke T and Robinette M. Otoacoustic Emissions, Third Edition. Amsterdam: Thieme Publishers.
 
25. Hood LJ. 2007. Auditory neuropathy/dys-synchrony. In Eggermont, Don and Burkard. Auditory Evoked Potentials.
 
26. Hood LJ, Berlin CI. 2001. Auditory neuropathy (auditory dys-synchrony) disables efferent suppression of otoacoustic emissions. In Starr A and Sininger YS. Auditory Neuropathy. San Diego: Singular Publishing Group.
 
27. Hood LJ, Berlin CI. 2002. Clinical applications of otoacoustic emissions. In Berlin CI, Hood LJ, and Ricci A (Eds). Hair Cell Micromechanics and Otoacoustic Emissions: New Developments. San Diego: Singular Publishing – Thomsen Learning. Pp.121-137.
 
28. Hood LJ, Berlin CI, Bordelon J, Rose K. 2003. Patients with auditory neuropathy/dys-synchrony lack efferent suppression of transient evoked otoacoustic emissions. Journal of the American Academy of Audiology 14:302-313.
 
29. Hood LJ, Berlin CI, Hurley A, Cecola RP, Bell B.   1996. Contralateral suppression of click-evoked otoacoustic emissions: Intensity effects.   Hear Res 101:113-118.
 
30. Hood LJ, Berlin CI, Morlet T, Brashears S, Rose K, Tedesco S. 2002. Considerations in the clinical evaluation of auditory neuropathy/auditory dys-synchrony. Seminars in Hearing 23:201-208.
 
31. Hood LJ, Wilensky D, Li L, Berlin CI. 2004. The role of FM technology in the management of patients with auditory neuropathy/dys-synchrony. Proceedings of the International Conference on FM Technology, Chicago, Illinois.
 
32. Rose K, Hood LJ, Berlin CI. 2001. An overview of the evolution of auditory neuropathy – Its diagnosis and management. ASHA Special Interest Group Publication.
 
33. Starr A, Picton TW, Sininger Y, Hood LJ, Berlin CI. 1996.   Auditory neuropathy.   Brain, 119:741-753.
 
34. Sininger YS, Hood LJ, Starr A, Berlin CI, Picton TW. 1995. Hearing loss due to auditory neuropathy. Audiology Today 7:10-13.
 
35. Varga R, Avenarius MR, Kelley PM, Keats BJ, Hood LJ, Berlin CI, Morlet TG, Brashears SM, Starr A, Cohn ES, Smith RJ, Kimberling WJ. 2006. OTOF mutations revealed by genetic analysis of hearing loss families including a potential temperature-sensitive auditory neuropathy allele. J Med Gene. 43(7):576-581.
 

 

Copyright © 2014 by Vanderbilt University Medical Center    |    1211 Medical Center Drive    |    Nashville, TN 37232    |    (615) 322-5000
Vanderbilt University is committed to principles of equal opportunity and affirmative action.
This page was last updated June 4, 2009 and is maintained by Linda Hood